691426877 has 2 divisors, whose sum is σ = 691426878. Its totient is φ = 691426876.

The previous prime is 691426871. The next prime is 691426913. The reversal of 691426877 is 778624196.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 691374436 + 52441 = 26294^2 + 229^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-691426877 is a prime.

It is a super-2 number, since 2×691426877² = 956142252475946258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691426871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345713438 + 345713439.

It is an arithmetic number, because the mean of its divisors is an integer number (345713439).

Almost surely, 2^691426877 is an apocalyptic number.

It is an amenable number.

691426877 is a deficient number, since it is larger than the sum of its proper divisors (1).

691426877 is an equidigital number, since it uses as much as digits as its factorization.

691426877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 50.

The square root of 691426877 is about 26294.9971857766. The cubic root of 691426877 is about 884.2642877503.

The spelling of 691426877 in words is "six hundred ninety-one million, four hundred twenty-six thousand, eight hundred seventy-seven".